Method of making phonograph disks



P 1942- R. s., DEbl-l 2,295,938

. METHOD OFMAKING PHONOGRAPH DISK'S Original Filed June 24, 1941 I 2Sheets-Shget l Sept. 15, 1942. RS. DECH METHOD OF MAKING PHONOGRAPHDISKS Original Filed June 24, 1941 2 Sheet s-Sheet 2 anothermodification;

Patented 15, 1942 2,295,938 7 i N METHOD or MAKING PHONOGRAPH msxsRaymond S. Dech, Stamford, Coma, assignor to The Audio ManufacturingCorp Glenbrook, Conm, a corporation of Connecticut 1 Originalapplication June 24, 1941, Serial No. 399,501, now Patent No. 2,283,797,dated May Divided and this application March 24, 1942, Serial No.436,026

10 Claims.

This invention relates to new and useful im provements inmeth'ods ofmaking phonograph disks and has particular relation to an improvedmethod of making sound record blanks.

The objects and advantages of the invention will be apparent from aconsideration of the fol: lowing detailed description taken 'lnconnection withthe accompanying drawings. However, it

is to be understood that the invention is not limited to the detailsdisclosed butincludes all such :variations and modifications as fallwithin thev spirit of the invention andthe scope of the ap' I pendedclaims. 4

The present applicati 15a divisibn of y ap plication Serial Number399,501, filed June 24, 1941, now Patent Number 2,283,797 of 1942.

In the drawings: v t Fig. 1 is a face view of a phonograph disk made inaccordance with the methodof the invention; Fig. '2 is an enlargeddetail sectional view taken along the plane of the line 2-2 of Fig. 1:

Fig. 3 is a face view of a portion of a phonograph disk, with part of acoating broken away,

showing a modified construction of insert;

Fig. 4 is a view similar to Fig. 3 but showing Fig. 5 is a face view ofa modified construction -of insert or plug and on a larger scale-than inFig. 1; Fig. 6 is a face view of a portion of a phonograph diskcomprising an outer member and an sert and suggesting a modified methodof makti'sa viewsimilar to Fig. 5 but another modification;

Fig. 8 is a detail view showing a portion of a phonograph disk at onestep .in the improved process of manufacture; and

Fig. 9 is a somewhat similar view but showing the disk following anotherstepin its production.

showing May 19,

terial of a different nature, 1. e. a softer material such that anopening may be punched therein without likelihood of fracture of thematerial about such opening during or following the punching operation.Insert M has a phonograph disk locating opening 15 therethrough.

In making my phonograph disk a base I! of the desired diameter andthickness is provided in disk form. Thereafter the relatively largediameter opening I3 is cut or drilled in the base since (the base beingof glass or other rigid brittie substance) the opening cannot be formedby punching without breaking or fracturing the base Following theforming of opening I! one of the inserts I [is located in such opening.Preferably the insert is of fibre board, cardboard, metal,

or other material of a nature to permit of the punching of a hole orholes through it without danger of fracture of the material.

.Insert 14 may itself be punched from a sheet of stock. and thereafteror as part of the punching operation the insert is provided withslitsli"spaced apart and entering the insert from the outer peripheraledge-thereof. These slitsare relatively narrow and lend some resiliencyto the inserts whereby if the openings '13 vary slightly Referring indetail to the drawings a disk made according-to the methodoftheinvention is shown in Figs. 1 and 2 and steps in the method of makingsaid disk being illustrated in Figs. 8

and 9. The complete disk is generally designated l0 and comprises adiskshaped basev or mem- 'ber ilhaving on either or both sides a coatingH of lacquer or: other material adapted to have" a sound groove engravedorcuttherein or having sound grooves therein. Base H has a rather large:diameter opening I! therethroug h-and a plate-like insert I4 is securedin said opening. I

Base or memberllis of a frangible orfra'ctu're 1 ,able materiaLas glass,and insert I4 is of atrian in size,;are not exactly circular,v or. haverough edges, or the like, the inserts may be sprung into place in theopenings and will adjust themselves to the sizes-of the openings intowhichthey are sprung.

. After the insert'is in the opening 13, where it is retained byengagement with the edges of the opening, the coating Ii is applied.This coating is usually appliedfirst to.one side and .then to the otherof the disk. The coating is continuous over each side of the base 12 andthe insert M. This leaves the insert securely enclosed by a film on eachof its sides and some other coating materialmay enter between the,contiguous edges of the insert andopening, as at- I], ,to further securethe insertin place. Spacefor the coating at I! may result from deformingof the-insert,

from the latter having a broken or interrupted edgeorfrom the fact thatthe edge of the opening. l3-is generally rough. Further the coatingmaterial entersthe slits l6 filling the same and establishing aninterlocking connection betweenthe insert and the coating.

- Fig. 8 shows the insert in place in the opening 1 [3 of the basepriorto. the coating of the illustratedside' of the disk. Fig. 9 showsthe next step inthe making of the improved phonograph disk and in suchfigure the coating H ha's'been applied to the illustrated side of thebase and insert. When the coating has been applied to both sides of thedisk the next and final step is In such operation the outer edges of maybe punched in the desired predetermined relation to the outer edge ofthe disk and usually exactly centrally of the disk.

Locating opening I is preferably punched after the coatings have set andtherefore when the opening has been made the disk is completed and readyfor use. If this opening I5 is made at any time prior to the setting ofthe coatings the latter are likely to run into the opening so that thelatter would then have to be reamed out or otherwise again treated tomake the disk ready for use. Further since opening [5 is made bypunching its dimensions may be very accurately controlled.

Owing to its flatness, its smoothness and its rigidity glass ispreferred for the making of the base [2. However, other materials may beused. The use of glass or other fracturable or frangible materialspresents some problems that heretofore have restricted their use inmaking phonograph disks. Among the difliculties not heretofore overcomewas the making of a satisfactory and serviceable locating or mountingopening, as the turntable spindle receiving opening, in the disk. Thisproblem I have overcome.

Base or member l2 may be of any diameter, as, for example, 8, 10, 12,16, etc., inch phonograph disks and is usually approximately onesixteenth of an inch in thickness. Opening I3 is of the desireddiameterand the inserts B4 are preferably of a diameter to have a snugfit in such openings. Slits l6 are'in the neighborhood of .005 of aninch in width although this may depend on the diameter, thickness andmaterial of the insert. These slits extend into the insert a distance tohave the latter somewhat resilient whereby they may be sprung intoopenings of slightly smaller diameter or having rough edges or that arenot exactly round. With the described structure the inserts will retainthemselves in place during the coating operations.

Regardless of the outside diameter'of the base [2 it is preferred tohave the opening 13 of one diameter in all basesso that inserts l4 ofbut one diameter need be made up and kept on hand for all diameters ofphonograph disks. These inserts M are located within the sound groovearea of the disk it being understood that the sound grooves in a recordwill be between the outer periphery of the base l2 and the insert I4.

It is here noted thatjhe base I2 is of a nonpunchable or fracturablematerial while the ininsert l4. The insert is inwardly of the soundgroove area of the disk and is provided with slits 24 for the purpose ofthe slits l6 of Figs. 1 and 2. A sound .groove receiving coating 25 isapplied to each side of base 2| and insert 23 and seals the latter inplace.

From the above it will be understood that insert 23 is much like insertl4 and the difference resides in the fact that insert 23 in addition tothe central locating opening 26 is provided with three other locatingopenings 21. openings are formed by punching and usually as the finalstep in the making of the disk. One ormore of the openings 21 is to beused in connection with an eccentric driving pin on the turntable of aphonograph.

To accommodate the additional openings 21 the insert 23 may be ofgreater diameter than insert l4 although the diameter of the elements isa matter of choice or convenience. Any desired number of locations ofthe extra openings 21 may be provided and the disk may be used with aturntable not provided with a driving pin or driving pins if that isdesired.

In the modification of Fig. 4 the disk 30 comprises a base 3| of glassor the like. This base has a plurality of relatively largediameter-openings 32, 33, and 34 drilled therethrough and each receivingan insert 35 similar to the insert l4 first described. Inserts 35 havethe slits 36 and locating openings 38 corresponding with the slits l6and locating opening l5 of insert l4. Continuous coatings 31 of lacqueror other sound groove receiving material are applied to each side ofbase 3| and the inserts 35 and fill the slits 36 and seal the inserts inplace. The final step in the making of disk 30 is the punching of thelocating openings 38 inthe inserts 35.

All of the inserts 35 are located within the .sound groove area of thedisk 30 and the inserts may be in the, desired positions relative to oneanother. For example, one insert may be so disposed that its opening 38will be punched concentric with the outer periphery of disk 30 while theother inserts have their openings located for cooperation with eccentricdriving pins on a turntable.

The insert 40 of Fig. 5 may be used in place of any of the insertspreviously described and comprises a body 4| made of fibre board,cardboard, metal or the like punchable material and has its edgeroughened as by being milled or serrated at 42. Insert 40 having anuneven or broken edge may be forced into an opening slightly smallerthan the greatest diameter of the insert and will frictionally retainitself in place 'during the coating operation. Portions of the lacquercoating material wiil'fiow into the milled slots or serrations lockingthe insert to the coating. Thus insert 40 maybe substituted for any ofthose previously described and may have one or more locating openingspunched therein as the final step in the making of a disk.

Fig. 6 suggests a modified process or method of making a phonographdisk. There the disk, generally designated 45, includes a base 46 ofglass or other fracturable material in which is cut or drilled arelatively large diameter opening 41. An insert 48 is provided to have aloose fit in opening 41 and is of the material previously described foruse 'in making inserts.

Insert 43 being solid without slits or a rough or broken edge hasnoresiliency. Since it is purposely made small it has a loose fit in theopening 41. In making disk 45 insert 48 is adhesively held in place andthe sides of the base,

All of these ventlongpwhat I claim is:

tape may be left in place or removed from base and insertandthe secondside of the disk coated. In the coating operation some of the coatingmaterial flows into the slight space heand eifectively seals theinsertin place. after a locating opening or openings is punched in the insert.

Fig. 7 shows another modification'of insert Thereor are 2,295,9sa thetween the insert and the edge of the opening 41 reception of a soundgroove and the latter is sealed to the former, and then punching agenerally designated 50 and adapted to be subi0 stituted for any of theinserts previously described when making a phonograph disk. In-

sert 50 is a disk relieved along a portion of its edge whereby it. isnot a true circle but has a slightly greater diameter along the line AB5 than along the line CD. That is, over a considerable are as suggestedby the distance between the dotted line 5| and the full line 52, thedisk is relieved.

cating opening in said insert.

3. The method of making a phonograph disk comprising drilling an openingin a body member of fracturable material, placing an insert ofnonfracturable material in said opening in frictional engagement withthe edges thereof, and then sealin'g said insert in place with a film ofsound groove receiving material extending onto both For example, wherethedisk has a diameter 3 along the line A-B of .750 inch it has beenfound satisfactory to reduce it over an arc of approximately 120 degreesto have its diameter along the line C-D approximately .740 inch.

These dimensions are only suggested and are not to be considered aslimiting.

A slit 53 is formed in the disk and extends in the direction of theshort diameter thereof entering from one edge and preferably extending6- more than one-half the distance'across the in- V sert. Owing to thepresence and location of 3 this slit 53 the insert may have its diameteralong the line A-B reduced by squeezing its portions inwardly reducingthe width of the slit 'or even closing the'open end portion thereof.

Thus it will be understood that insert 50 may be inserted into anopening which isnot truly circular or which is of a diameter less thanthat of the insert when measured along the line 4 A-B and that the diskwill expand and hold itself in place in an opening into which it has.beenplaced. The insert 50 has certain manufacturing advantages over theinsert l4 but other-- the member. I i

6. The method of making a phonograph disk comprising forming an openingin a body memwise itmay be substituted for-any of the inserts 45heretofore described.

It is to be understood that in the foregoing description and in theappended claims the words phonograph disk are used to designate either aform of a disk. Additionally it is pointed out that the insertspreferably are of a thickness to lie within the planes represented bythe side surfaces ofthe base so that a series of the completed disks maybe stacked one on the other i and lie fiat so that they may be handledwithout breakage should they be tightly gripped while 'so stacked. Atrade-name or trade-mark or the like may be-stamped or embossed in. oron the the member and insert.

4. The method of making a phonograph disk comprising drillingan openingin a body member offracturable material, placing an insert ofnon-fracturable material in said opening, adhesively supporting saidinsert in said opening, and then sealing said insert in place with afilm of sound groove receiving material extending onto both the memberand insert.

5. The method of making a phonograph disk comprising forming an openingin a body member of fracturable material, sealing an insert ofnon-fracturable material in said opening,-and then punching an openingthrough the insert in predetermined relation to the outer edge of ber offracturable material, then placing a com- ,pressible insert in saidopening and permitting the insert to expand into engagement with theedges of the opening, and then sealing the insert 0 tosaid member byafilm extending onto both the member and insert.

'7 The method of making a phonograph disk comprising forming an openingin a body member of fracturable material, placing an insert of pliantmaterial in saidopening and locking it .therein by expansible means, andthen sealing said insert in said opening and covering the sides soundrecord or a sound record blank, in the 50 insert of puncl'iable materialwithout damage to the completed disk.

Having thus set forth the nature of my in- 1. The method of making aphonograph disk material, applying a-fllm of sound groovereceivcomprising forming a large opening in a member offracturablematerial, placing in said opening an insert of amaterial adapted to havean opening L punched therein without causing fracture of the in:material to said member and said insert and -thereby sealing the latterin place, and then punchinga'locating opening in said insert. 2. Themethod of making a phonograph disk I comprising formins a large openingin amember of said body with films of sound groove receiving material. I

8. The method of making a phonograph disk "comprising forming an openingin a disk of fracturable material, placing an insert of non-fracturablematerial in said opening, and locking the insert in said opening byexpansible means and a film of sound groovereceiving materialextending'over one side of said member and onto said insert.

9. The method of'making a phonograph disk comprising forming a pluralityof openings in a body member of fracturable material, placing an insertof non-fracturable material in each ofsaid openings,and then sealing allof saidinserts in place with films of sound groove receiving materialapplied to each. side of said member and extending onto said inserts.

10. The method of making a. phonograph disk comprising forming a largeopening in 'a member of fracturable material, placing in said openinganfinsert of non-fracturablematerial, applying "to each side of saidmember and said insert in liquid form a coating of a material adaptedtosetand form a film of sound groove receivin material on said member.

- RAYMOND s. neon.

